AT90CAN64-16AUR Atmel, AT90CAN64-16AUR Datasheet - Page 33

• Manufacturer Part Number: AT90CAN64-16AUR
• Description: MCU AVR 64K FLASH 16MHZ 64TQFP
• Manufacturer: Atmel
• Series: AVR® 90CANr

Specifications of AT90CAN64-16AUR

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 16MHz
• Connectivity: CAN, EBI/EMI, I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 53
• Program Memory Size: 64KB (64K x 8)
• Program Memory Type: FLASH
• Eeprom Size: 2K x 8
• Ram Size: 4K x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 5.5 V
• Data Converters: A/D 8x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 64-TQFP, 64-VQFP
• Data Bus Width: 8 bit
• Data Ram Size: 4 KB
• Mounting Style: SMD/SMT
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

4.5.7
7679H–CAN–08/08
External Memory Control Register B – XMCRB
• Bit 3..2 – SRW11, SRW10: Wait-state Select Bits for Upper Sector
The SRW11 and SRW10 bits control the number of wait-states for the upper sector of the exter-
nal memory address space, see
• Bit 1..0 – SRW01, SRW00: Wait-state Select Bits for Lower Sector
The SRW01 and SRW00 bits control the number of wait-states for the lower sector of the exter-
nal memory address space, see
Table 4-4.
Note:
• Bit 7– XMBK: External Memory Bus-keeper Enable
Writing XMBK to one enables the bus keeper on the AD7:0 lines. When the bus keeper is
enabled, it will ensure a defined logic level (zero or one) on AD7:0 when they would otherwise
be tri-stated. Writing XMBK to zero disables the bus keeper. XMBK is not qualified with SRE, so
even if the XMEM interface is disabled, the bus keepers are still activated as long as XMBK is
one.
• Bit 6..4 – Reserved Bits
These are reserved bits and will always read as zero. When writing to this address location,
write these bits to zero for compatibility with future devices.
• Bit 2..0 – XMM2, XMM1, XMM0: External Memory High Mask
When the External Memory is enabled, all Port C pins are default used for the high address byte.
If the full address space is not required to access the External Memory, some, or all, Port C pins
can be released for normal Port Pin function as described in
all 64KB Locations of External Memory” on page
access all 64KB locations of the External Memory.
Bit
Read/Write
Initial Value
SRWn1
0
0
1
1
1. n = 0 or 1 (lower/upper sector).
For further details of the timing and wait-states of the External Memory Interface, see Figures
4-6 through Figures 4-9 for how the setting of the SRW bits affects the timing.
SRWn0
XMBK
Wait States
0
1
0
1
R/W
7
0
Wait States
No wait-states
Wait one cycle during read/write strobe
Wait two cycles during read/write strobe
Wait two cycles during read/write and wait one cycle before driving out new
address
R
6
–
0
(1)
R
5
–
0
Table
Table
4-4.
4-4.
R
4
–
0
R
3
–
0
35, it is possible to use the XMMn bits to
XMM2
R/W
2
0
AT90CAN32/64/128
Table
XMM1
R/W
1
0
4-5. As described in
XMM0
R/W
0
0
XMCRB
“Using
33